The authors have developed a structural mathematical model in a series of papers, that is deduced theoretically from the model of simplified vortex systems with ring vortex, horse-shoe vortex and cross-flow vortex. This model describes the ship hydrodynamic forces X , Y and N acting on a hull in turning motion, with small to large drift angles using the “component type” mathematical model. The new model is able to estimate the forces in a larger drift angle 3090 degrees, and even in turning motion, by analyzing the hydrodynamic data of oblique towing motion with small drift angle 030 degrees. This paper presents a more accurate mathematical model for practical use, with simple empirical corrections of the previous model.